Abstract: The spatio-temporal dynamics of population and its impact on the regional ecosystem quality in Beijing were analyzed at city-county-township hierarchical levels during 2000 to 2010, based on the 5^th and 6^th population census data and MODIS-NDVI thematic data. We found that the resident population of Beijing increased by 43.9% during the study period, and the trend of population gathering to the urban fringe resulted in an obviously circular distribution. The annual maximum NDVI of Beijing had the trend of increase, however, decreased significantly between the 5^th Ring and the 6^th Ring. The change trends of NDVI in urban and exurban areas showed significantly negative relationships with the change ratios of population density, respectively. The increment of urban population caused by urbanization did not show negative influence on the regional ecosystem quality of Beijing. On the contrary, the ecosystem quality in urban core and exurban areas was improved, due to the adjustment of city functions and the population transfer from rural to urban area. Therefore, the functional orientation and development mechanism were the main contribution to the evolution of population pattern and its ecological impacts.